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Vacuolar proton‐pumping pyrophosphatase in Beta vulgaris shows vectorial activation by potassium
Author(s) -
J M Davies,
P A Rea,
D Sanders
Publication year - 1991
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(91)80085-h
Subject(s) - vacuole , pyrophosphatase , cytosol , chemistry , inorganic pyrophosphatase , membrane , biophysics , biochemistry , potassium , proton , beta (programming language) , proton transport , cytoplasm , biology , enzyme , physics , pyrophosphate , organic chemistry , quantum mechanics , computer science , programming language
Previous work with membrane visicles has demostrated an absolute dependence on K + for proton translocation by the inorganic pyrophosphatase (H + ‐PPase: EC 3.6.1.1) from the vacuolar membrane (tonoplast) of higher plants. Using intact vacuoles from sugar beel ( Beta vulgaris ) storage tissue, we have monitored PP,‐dependent currents by patch clamp in ‘whole vacuole’ mode. Serial K + substitutions were made are both tonoplast faces. The results show that K + activation occurs only at the cytosolic face.